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Building tunnels takes expertise and hard work: experts

It’s not so easy to build a tunnel like the one discovered at York University near the Pan Am Games site, experts say.

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The tunnel was found on Jan. 14 by a conservation officer in the heavily wooded area near the Rexall Centre at York University Campus, near the future site of the Pan Am Games, said Deputy Chief Mark Saunders.(Provided)

It’s not easy to build a tunnel like the one found near a Pan Am Games venue at York University, experts say.

“It’s quite amazing,” said McMaster University engineering professor Peijun Guo, who studied police photos of the site and was particularly impressed by the supports and arched ceilings inside its inner chamber.

While the inner chamber is well buttressed, the entranceway lacks supports, as if the builders didn’t want it to be noticed.

The degree of difficulty in constructing such a tunnel is beyond what one would expect from a first-year engineering student, said professor Mamadou Fall, who teaches engineering at the University of Ottawa.

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A fourth-year engineering student might be up to the job, according to Fall, whose specialties include geotechnical engineering, which includes excavation skills.

Engineering experts say it takes some training - or risky trial and error - to produce a tunnel as well buttressed as the one found near a future Pan Am Games venue. (Toronto Police Service)

“You’d need expertise in geotechnical engineering.”

The tunnel was found in a heavily wooded area 25 metres from the entrance to the Rexall Centre. It had plywood supports, a sump pump, a generator and special moisture-resistant lightbulbs, police said.

Expertise to build a tunnel can be gained through trial and error, if the digger doesn’t mind running some risk, said Julio Angel Infante Sedano, a professor in the University of Ottawa’s engineering department.

The important thing is to reinforce soft soil with materials such as wood, concrete and metal as you dig, to prevent collapse, Infante said.

Such skills could be learned on the job in construction and not necessarily in a classroom, he said.

“It’s an expertise you could come about through trial and error, but the risk is greater,” Infante said. “Mines like this and tunnels like this have been dug since ancient times.”

The experts say it’s very tough to estimate how long it would take to build.

With optimum soil conditions, equipment and expertise, it might be done in a day. Worse soil, equipment or expertise could stretch the task out to a month or so.

Guo said the soil appeared claylike in the police photos. That means two men with shovels might be able to dig out the tunnel in a couple of weeks.

The easiest digging is for soft ground tunnels, built in soft earth or soft rock such as sandstone, and clay.

Shovels and buckets have been used for centuries to build tunnels.

Back in the 16th century, Ivan the Terrible used tunnels packed with gunpowder to defeat the Tartars.

Tunnels were sometimes used along the Underground Railroad route by slaves escaping to freedom from the southern U.S. states before the Civil War. Most were built under the homes of people who sheltered fugitive slaves.

In World War I, tunnel builders — called “sappers” — used shovels to create secret entrances to German trenches at the Western Front.

In the Vietnam War, North Vietnamese soldiers used shovels to dig elaborate tunnel networks to hide from and attack U.S. soldiers.

In 2005, American prison guards at the Bucca Detention centre in southern Iraq foiled a plot to bust out 6,000 prisoners through a tunnel.

Vaughan resident Carmelo Bruzzese had an underground bunker in his Southern Italian home, according to Italian authorities. Bruzzese is currently in custody, fighting extradition to Italy, where he has been named in an anti-Mafia investigation.

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